1. Be respectful – no electronics please!
Announcements
Exam scores posted late tonight! Get graded exams back tomorrow in discussion.
Pre/post lecture assignments due as usual Tuesdays & Thursdays at 8:00 am
Workshop in lab on Monday (completion credit)
Bring a textbook to class on Monday!

2. Most Missed Question (55% Missed)

3. Consider a substance, which can exist in multiple phases: in terms of particle movement…
Which phase has highest energy?
A solid
A liquid
A gas
All the same
Which phase is most stable?
A solid
A liquid
A gas
All the same

4. Clicker #1
Is a racquetball frozen by liquid nitrogen an endothermic or exothermic process? (The system is underlined.)
A) endothermic
B) exothermic

5. Clicker #2
Is the boiling of water an endothermic or exothermic process? (The system is underlined.)
A) endothermic
B) exothermic

6. Clicker #3
Ba(OH)2·8H2O(s) + 2NH4SCN(s)  Ba(SCN)2(aq)+ 2NH3(g)+ 10H2O(l)
Is the reaction of the two solids in the beaker an endothermic or exothermic process?
A) endothermic
B) exothermic

7. Clicker #4 Which is lower in potential energy? H2/O2 or H2O A) H2/O2
B) H2O

8. Clicker #5
Which is more stable?
H2/O2 or H2O
A) H2/O2
B) H2O

9. Overall goal: Atomic Structure Chemical Bonding 3D Molecular Structure
Molecular Properties